It is known that two or more vehicles moving along a roadway can cooperate as a road train or a “platoon” for mutually providing various efficiency benefits to the vehicles within the platoon. A typical vehicle platoon includes a leader vehicle and one or more follower vehicles arranged serially along a single roadway lane. Larger platoons can involve many follower vehicles for spanning multiple lanes thereby providing enhanced efficiency to more vehicles. However, ensuring the safety of both the platooned vehicles as well as of the other non-platooning vehicles on the roadway usually dictates the short single lane platoon incarnation.
The aerodynamic geometry of a group of vehicles arranged in a platoon provides wind resistance loss benefits superior to the aggregated individual wind resistance losses of the vehicles when travelling separately. A maximum aerodynamic benefit and resultant fuel savings is realized by the vehicles maintaining a small inter-vehicle distance or spacing in terms of reduced energy consumption. However, holding a tight head-to-tail distance or spacing between platooned vehicles requires that careful attention be paid to various functional or environmental and operational characteristics and capabilities of the vehicles and other external conditions including for example the overall size of the platoon, weather conditions, relative braking abilities between vehicle pairs, relative acceleration abilities, relative load or cargo size and weight including required stopping distance, and the like. Special attention must also be paid to characteristics of the roadway such as roadway incline, decline, and turn radii. These various parameters implicate directly or indirectly the inter-vehicle safety considerations as well as the overall safety of multiple vehicle platoons.
In the single lane platoon incarnation described above, the vehicles participating in a platoon typically mutually cooperate to maintain a relatively fixed and constant (even or the same) distance between adjacent vehicles by exchanging deceleration command and other signals between adjacent vehicles of the platoon. On flat roadways, the even distance maintained between the vehicles is often fixed and constant in accordance with control protocols using combinations of global positioning systems (GPS) data sharing, deceleration command signal exchanges, and safety and efficiency algorithms. In any case, the relative distance between the vehicles of the platoon preferably remains substantially even, constant or the same in accordance with platoon control mechanisms and protocols in place.
For maintaining the preferred relatively fixed and constant (even or the same) distance between adjacent vehicles, many commercial vehicles that participate in platoons are highly sophisticated and are also equipped with adaptive cruise control (ACC) systems including forward and rearward sensors used for maintaining a safe relative distance between a host vehicle and a forward vehicle, and collision mitigation (CM) systems for avoiding or lessening the severity of impacts between a host and forward and rearward vehicles using various combinations of transmission, vehicle retarder, and foundation brake controls.
Currently, the technique for vehicles participating in a platoon to share their position with other vehicles of the platoon involves determining, by each vehicle, its own GPS coordinate data, broadcasting by each vehicle its own GPS coordinate data to all of the other vehicles of the platoon using over-the-air communications (such as the J2945/6 communications), and receiving the GPS position data from all of the other vehicles of the platoon. In this way, each vehicle of the platoon knows the position(s) of each other vehicle of the platoon. The GPS coordinate data is then used by each vehicle to, among other things, establish the relatively even distance coordinated between the vehicles as generally described above.
Platooning vehicles follow each other on the roadway in close proximity to each other and often at highway speeds as explained above, and for this they typically use a Radar to control the inter-vehicle distance(s). For emergency braking situations such as Autonomous Emergency Braking (AEB) events for example, forward-directed cameras and/or other sensor(s) on a following vehicle may detect the actuation by a forward vehicle of a rearward facing brake light so that appropriate emergency stopping or other actions can suitably be initiated.
Platoons that operate on public roadways, however, sometimes encounter conditions that require more complicated platoon arrangements and brake monitoring and platooning control and maintenance operations. The close distance between the platooning vehicles poses a risk when the lead vehicle has to decelerate in an emergency situation such as might be required by stopping forward traffic. Therefore in the interest of protecting the platooning vehicles from inadvertent collision with each other, a particular platoon order or arrangement has been devised. More particularly, many platoons are ordered so that the platoon vehicle that is least capable of deceleration is placed at the front of the platoon. This helps to mitigate the chance that the one or more platoon follower vehicles will be unable to adequately decelerate in order to avoid a collision with the platoon leader vehicle. In this platoon topology, the platooning vehicle having the lightest or least braking capabilities or parameters is located at the front of the platoon chain, the vehicle having the highest braking capabilities or parameters is located at the back or rear of the platoon chain, and any one or more intermediate vehicles are arranged from front to back in an order of increasing braking capabilities or parameters. This platoon topology also gives each rearward or following vehicle more time gap for braking in turn relative to the next immediately forward or leading vehicle.
In roadway vehicles, however, braking efficiency is affected by many factors such as brake temperature, brake type, burnishing, vehicle weight, number of tires, tire wear, vehicle loading, road surface type and weather conditions. In addition, the braking efficiency of any vehicle can also change over time, and also can change differently for each vehicle. One or more changes in braking capabilities and any other braking performance characteristics of a first vehicle of a set of platooning vehicles does not necessarily imply that any of the other vehicles of the set of platooning vehicles are experiencing the same one or more changes. That is, one or more changes in braking capabilities of any single vehicle in a platoon cannot reliably be imputed any of the other vehicles of the platoon. This makes management of inter-vehicle gap distances between the platooning vehicles dynamic and therefore more difficult.
Platooning vehicles may be of a single body form such as a panel truck or of a combination vehicle form. A combination vehicle typically comprises a towing vehicle such as a commercial vehicle tractor towing one or more towed vehicles such as one or more commercial vehicle trailers. Currently, towing vehicle safety systems use a “non-enhanced” braking mode when responding to autonomous brake signals because ABS functionality of the one or more towed vehicles is indeterminate. The non-enhanced braking mode pulses the braking signal from the towing vehicle of the combination vehicle to the one or more towed vehicles in order to prevent potential instability. In general, the non-enhanced braking mode applies a first level of braking force to the one or more towed vehicles in a predetermined reduced proportion relative to the level of braking force applied to the towing vehicle by the towing vehicle's safety system.
Use of the non-enhanced braking mode as a default braking mode of operation when the braking capabilities of the one or more towed vehicles is indeterminate or when functional ABS cannot be established may present a problem while platooning, however, because it might sometimes be necessary and/or desirable for a following vehicle to apply more braking force to the one or more towed vehicles than the first level of braking force of the non-enhanced mode would allow or otherwise permit. This situation could potentially result in an unnecessary collision between the vehicles when the one or more towed vehicles of the combination vehicle are in fact capable of safely responding to braking forces above the first level of the non-enhanced mode even though their functional ABS is indeterminate or cannot be established by the towed vehicle. In some cases, the one or more towed vehicles of the combination vehicle might be capable of safely responding to braking forces above the first level of the non-enhanced mode for short periods of time thereby avoiding a collision with an adjacent platooning vehicle, even though their functional ABS is indeterminate or cannot be established by the towed vehicle.
Given the above, therefore, it is highly desirable to provide a system and method for resolving the capabilities of the one or more towed vehicles so that either the non-enhanced or the enhanced braking modes can be implemented. In particular, it is desirable to provide a system and method for resolving the capabilities of the one or more towed vehicles based on a verification of capabilities reported by the towed vehicles relative to an expected capabilities set or state.
It would be desirable to provide a system and method to selectively enhance the level braking of the one or more towed vehicles of a combination vehicle as may be necessary and/or desired above the first level of braking that would be available in the non-enhanced braking mode.
It would further be desirable to provide a system and method to selectively enhance the braking of the one or more towed vehicles to effect in certain circumstances an “enhanced” braking mode when the braking capabilities of the one or more towed vehicles can be determined or otherwise verified, wherein the enhanced braking mode applies a second level of braking force to the one or more towed vehicles of the combination vehicle greater than the first level of braking force that would otherwise be applied in the non-enhanced braking mode.
It would still further be desirable to provide a system and method to selectively enhance the trailer braking to effect the enhanced braking mode when the braking and/or other functional capabilities of the one or more towed vehicles as reported by the one or more towed vehicles can be verified relative to an expected set of braking and/or other functional capabilities.
It would still yet further be desirable to provide a system and method to selectively enhance the trailer braking to effect the enhanced braking mode when the braking and/or other functional capabilities of the one or more towed vehicles as reported by the one or more towed vehicles can be verified relative to an expected set of braking and/or other functional capabilities received from an operator of the towing vehicle, and to effect the non-enhanced braking mode when the braking and/or other functional capabilities of the one or more towed vehicles as reported by the one or more towed vehicles cannot be verified relative to the expected set of braking and/or other functional capabilities received from the operator of the towing vehicle.
It would be desirable to receive the expected set of braking and/or other functional capabilities from the operator of the towing vehicle by a human interface circuit operatively coupled with the towing vehicle. It would be desirable in particular for the human interface circuit to include human interactive components such as for example one or more of a touch screen disposed in or operatively coupled with the towing vehicle of the combination vehicle, a dashboard console disposed in the towing vehicle of the combination vehicle, a headliner console disposed in the towing vehicle of the combination vehicle, and/or a cellular phone interface disposed in or operatively coupled with the towing vehicle of the combination vehicle.
It would still further yet be desirable to provide a system and method to selectively enhance the trailer braking to effect the enhanced braking mode when the braking and/or other functional capabilities of the one or more towed vehicles as reported by the one or more towed vehicles can be verified relative to an expected set of braking and/or other functional capabilities received by the towing vehicle from an associated source other than the operator, and to effect the non-enhanced braking mode when the braking and/or other functional capabilities of the one or more towed vehicles as reported by the one or more towed vehicles cannot be verified relative to the expected set of braking and/or other functional capabilities received by the towing vehicle from the associated source other than the operator.
It would be desirable to receive the expected set of braking and/or other functional capabilities from associated source other than the operator of the towing vehicle by a wireless communication circuit operatively coupled with the towing vehicle. It would be desirable in particular for the wireless communication circuit to be one or more of a wireless networking WiFi communication circuit receiving wireless WiFi signals, a wireless Bluetooth communication circuit receiving wireless Bluetooth signals, a wireless dedicated short range communications (DSRC) communication circuit receiving wireless DSRC signals, an LDP433 communication circuit receiving wireless LDP433 signals, a radio frequency (RF) communication circuit receiving RF signals, a wireless cellular communication circuit receiving wireless cellular communication signals, a wireless satellite communication circuit receiving wireless satellite communication signals, one or more associated camera devices, one or more radar devices, and/or one or more Light Detection and Ranging (LIDAR) sensor devices.